Rotary fluid device



June 3, 1969 E. L. FARRIS 3,447,476

ROTARY FLUID DEVICE Fild May 25, 1967 EDWARD L. fZ/P/P/S June 3, 969 E.L. FARRIS 3,447,476

ROTARY FLUID DEVICE Filed May 25, 1967 Sheet 2 of 2 ,yi; (awn ATTO/PA/EY United States Patent 3,447,476 ROTARY FLUID DEVICE Edward L.Farris, Baldwin Park, Calif. (12251 Bluebell Ave., Garden Grove, Calif.92640) Filed May 25, 1967, Ser. No. 641,246 Int. Cl. F04c 1/04, 21/08US. Cl. 103136 8 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates generally to fluid pressure devices. More particularly, theinvention relates to a radial vane type rotary fluid pump and motordevice characterized by novel rolling ball sealing vanes.

Rotary fluid motors and pumps of the class to which this inventionpertains are well known in the art. Generally speaking, such a rotaryfluid pressure device comprises a rotor member and a stator member whichare mutually supported for turning of the rotor on an exis of rotationrelative to the stator. One member, i.e. the outer member, has a sealedcasing containing the other, inner member, whereby the members haveconfronting circumferential surfaces. Extending radially between themembers are a number of uniformly circumferentially spaced sealing vaneswhich are carried by one member, for radial extension and retractionrelative thereto, and are retained in fluid sealing relation to theconfronting circumferential surface of the other member. In most rotaryfluid motors and pumps of this kind, for example, the outer casingmember forms the stator, and the inner member carries the radial sealingvanes and forms the rotor. The inner and outer members and the sealingvanes define a number of working fluid chambers between the adjacentvanes and uniformly circumferentially spaced about the axis of relativerotation of the members.

The radial distance between the rotation axis of the members and theinner circumferential wall of the outer casing member variesprogressively around the axis in such a way that during rotation of therotor, each working chamber undergoes alternate expansion andcontraction. The casing is provided with fluid ports which open to theinterior of the casing for successive communication with the workingchambers during their expansion and contraction modes, respectively.Pump operation of such a fluid pressure device is accomplished bydriving the rotor from an external power source. Motor operation isaccomplished by supplying high pressure working fluid to the appropriatefluid port of the device.

A major disadvantage of the existing rotary fluid pumps and motors ofthe character described resides in the relatively high frictional losseswhich occur during their operation. These fractional losses result fromthe fact that the sealing vanes employed in the existing pumps andmotors commonly comprise plates, or the like, which are urged into fluidsealing relation with and slide along coacting sealing surfaces. Inaddition to undesirable friction loss, of course, such sliding vaneaction produces excessive Wear and shortens service life.

It is a general object of this invention to provide an improved radialvane-type rotary fluid pump and motor which avoids the above-noted andother disadvantages of the existing fluid pumps and motors of this kind.

A more specific object of the invention is to provide an improved radialvane-type fluid pump and motor wherein the sealing vanes comprisespherical rollers or balls which undergo a rolling motion along theirmating sealing surface, during relative rotation of the rotor andstator, in such a way as to minimize friction loss and wear and maximizeoperating efliciency.

A further object of the invention is to provide a rolling ball vanerotary fluid pump and motor of the character described which isrelatively simple in construction, reliable in operation, and otherwiseideally suited to its intended purposes.

Other objects, advantages, and features of the invention will becomereadily evident as the description proceeds.

With these and such other objects in view, the invention consists in theconstruction, arrangement, and combination of the various parts of theinvention, whereby the objects contemplated are attained, as hereinafterset forth, pointed out in the appended claims, and illustrated in theaccompanying drawings.

In these drawings:

FIGURE 1 is a side elevation of a rolling ball vane type rotary fluidpump and motor device according to the invention;

FIGURE 2 is an enlarged section taken on lone 22 in FIGURE 1;

FIGURE 3 is a section taken on line 3-3 in FIG- URE 2;

FIGURE 4 is a section through a modified rotary fluid pump and motordevice according to the invention;

FIGURE 5 is a section through a further modified pump and motor deviceaccording to the invention;

FIGURE 6 is a section taken on line 6-6 in FIG- URE 5; and

FIGURE 7 is an interior view of onehalf of the casing of the pump andmotor device illustrated in FIGURES 5 and 6.

In general terms, the invention provides a rotary fluid pump and motordevice, represented in FIGURES 1 through 3 by the fluid pump and motordevice 10, including an outer member 12 having a sealed casing 14.Within the casing 14 is an inner member 16 which is supported on thecasing for relative rotation of the members on an axis 'of rotation 18.One of the members, in this instance the outer casing member 12, isformed, within the casing, with a generally tubular circumferentialtrack 20 of substantially uniform and generally semicircular transversecross section. Track 20 opens radially, along one side, toward theother, inner member 16 and is bounded along its opposite side by acircularly curved wall 22. Track 20 as a longitudinal centerline 24, andthe track boundary wall 22 has a substantially constant radius ofcurvature about the centerline 24, along the entire length of the track.

The other member of the rotary fluid pump and motor 10, ie the innermember 16, is formed with a number of radial bores 26 which havesubstantially the same radius as and open axially to the track 20 in theouter casing member 14. Slidably fitted in the bores 26 are a number ofspherical rollers or balls 28 which function as and will be hereinafterreferred to as sealing vanes, or simply vanes. The ball vanes 28 projectaxially from their respective containing bores 26 into the track 20 andinto rolling, fluid sealing contact with the track boundary wall 22. Aswill appear presently, means are provided for retaining the ball vanes28 in the track 20, whereby the vanes undergo rolling motion along thetrack during relative movement of the members 12 and 16.

The outer member 12, inner member 16, and ball vanes 28 define a numberof fluid chambers 30 between the adjacent vanes and uniformlycircumferentially spaced about the inner member. The radial distancefrom the rotation axis 18 to the centerline 24 of the channel 20 variesprogressively along the channel, in such manner that during the relativerotation of the members 12 and 16, the ball vanes 28 undergo radialextension and retraction in their respective retaining bores 26, andeach fluid chamber 30 undergoes alternate expansion and contraction. Thecasing 14 of the outer member 12 is provided with fluid ports 32 and 34which open to the interior of the casing for successive communicationwith the chambers 30 during their expansion and contraction modes; thatis to say, port 32 communicates with the chambers bearing theirexpansion mode and port 34 communicates with the chambers during theircontraction modes. The arrangement of the present fluid pressure deviceis such that the latter is operative as a pump when the members 12, 16are driven in relative rotation by an external power source and as fluidmotor when high pressure working fluid is supplied to the port 32 of thepump.

Referring now in greater detail to the rotary fluid pump and motor ofthe invention which has been selected for illustration in FIGURES 1through 3, the outer member 12 forms the stator and the inner member 16forms the rotor of the device. The stator casing 14 is split, in aparting plane 36, into two mating halves 14a, 14b which are bolted toone another or otherwise joined. The two casing halves are sealed to oneanother with the aid of a gasket or other suitable sealing means (notshown). Rotor 16 of the fluid pressure device 10 has a generally flatdisc-shaped body 38 with parallel side faces 40 disposed in fluidsealing relation to the side walls 42 of the casing 14. Rotor 38 iscoaxially fixed to a shaft 44 which extends through and is rotatablysupported in bosses 46 on the casing side walls. Suitable sealing means(not shown) are provided for sealing the shaft to the casing.

In the illustrated fluid motor and pump device 10, the outer statorcasing 14 contains the tubular channel 20, and the inner rotor 16contains the ball,vane bores 26. Thus, the interior of the casing 14 hasa central region 48 which contains the rotor body 38 and isparametrically surrounded by the ohannel 20. This channel opens radiallyalong its inner side to the central casing region 48. As shown best inFIGURE 2, the peripheral edge of the rotor body 38 projects radiallyinto the channel through its open side. It is significant to note herethat the axial thickness of the rotor body is slightly less than thediameter of the channel and the outer circumferential edge of the bodyis rounded to a radius which is substantially the same as the radius ofcurvature of the channel boundary wall 22. It will be recalled that thediameter of the ball vane bores 26 in the rotor 16 and the diameter ofthe ball vanes 28 contained in these bores is substantially the same asthe diameter of the channel boundary wall 22 in the transverse crosssection.

As noted earlier, and as clearly shown in FIGURE 3, the radial distancefrom the rotation axis 18 of the rotor 16 to the centerline 24 of thestator channel 20 varies progressively around the channel. As aconsequence, the fluid working chambers 30 between adjacent ball vanes28 undergo alternate expansion and contraction, and the vanes themselvesundergo relative extension and retraction relative to the rotor body 38,during rotation of the rotor. Thus, in the particular fluid pressuredevice illustrated,

each working chamber undergoes an expansion stroke or mode duringrotation from A to B and a contraction stroke or mode during rotationfrom B to C in FIGURE 3. During rotation from C back to A, the workingchambers of the illustrated device remain in their fully contracted,minimum volume condition. This is due to the fact that the radialdistance from the rotor axis 18 to the stator channel centerline 24remains constant at its minimum value in the region between C and A.

It is evident, of course, that operation of the present fluid pressuredevice as both a pump and a motor requires the ball vanes 28 to remainwithin and move along the stator casing channel 20, in fluid sealingrelation to the channel boundary wall 22, during rotation of the rotor16. To this end, the angular extent of the channel boundary wall, intransverse section and about its centerline 24, is slightly in excess ofAlso, the side faces 40 of the rotor body 38 are formed with radialslots 50 aligned with the ball vane bores in the rotor and through whichthe ball vanes 28 in the bores project axially of the rotor into contactwith opposite sides of the channel wall, as shown best in FIGURE 2.Thus, the ball vanes are captivated or caged in the channel 20 forrolling movement along the channel and against inward radial movementfrom the channel through its inner openside. To further aid in retainingthe ball vanes in fluid sealing relation with the channel boundary wall22, the inned ends of thhe ball vane bores 26 communicate via passages52 with body 38. Successive inward movement of the rotor vanes 28 intheir respective bores 26, therefore, displaces fluid from these boresinto the other ball vane bores to urge the ball vanes 28 in the latterbores outwardly into fluid sealing relation with the channel boundaryWall 22.

During operation of the fluid pressure device 10 as a pump, the rotorshaft 44 is coupled to a power source for driving the pump rotor 16 ineither direction in FIGURE 3. Assuming clockwise rotation of the rotorin FIGURE 3, it is evident that working fluid will be drawn through thecasing port 32 into the expanding working chambers 30 in the region A-B,and working fluid will be expelled from the contracting working chambersin the region B-C through the casing port 34. Driving of the rotor inthe opposite direction will effect a reverse pumping action. It issignificant to note that within the lower, constant radial distanceportions C-A of the casing channel 20, the rounded peripheral edge ofthe rotor body 38 is disposed in close proximity to the channel boundarywall 22 to provide the working chambers 30 with minimum volume withinthis region. It is for this reason that the edge of the rotor body isrounded to the same radius of curvature as the channel boundary wall.

Operation of the fluid pressure device 10 as a fluid motor isaccomplished by connecting one of the fluid ports 32, 34 to a source ofhigh pressure working fluid and the other port to a low pressure fluidreceiver. Under these conditions, the high pressure fluid entering eachexpanding working chamber 30 exerts a torque on the rotor 16 for drivingthe rotor in a direction to cause further expansion of the chamber untilthe latter eventually communicates with the low pressure port. Theworking fluid is then exhausted from the chamber during its subsequentcontraction.

The modified fluid pressure device 10a of FIGURE 4 is identical to thefluid pressure device 10 just described, except that the lower constantradial distance portion C-A of the ball vane channel 20 in the device 10is replaced, in the fluid pressure device 10a, by a lower channelportion, the radial distance of which from the rotor axis 18 varies inthe same manner as does the channel in the upper channel portion A-C.Also, the fluid pressure device 10a has additional fluid ports 32a, 34aopening to the lower channel portion so as to communicate successivelywith the working fluid chambers 30a in the lower channel portion duringthe expansion and contraction modes of the chambers which occur in thelower channel portion.

It will now be understood, therefore, that in the modifled fluidpressure device 10a, each working chamber 30a undergoes two expansionstrokes or modes and two contraction strokes or modes during eachrevolution of the rotor 16a, and the device produces elfective workingstrokes of the chambers throughout a full 360 of rotation of the rotor.Operation of the modified fluid pressure device as a pump isaccomplished by driving the rotor 16a from an external power source, asbefore. Fluid is then drawn into the pump through one pair ofdiametrically opposed ports 32a or 34a and is expelled through the otherports. Operation of the device as a motor is accomplished bycommunicating the corresponding ports 32a or 34a to a high pressurefluid source and the remaining ports to a low pressure fluid receiver.If desired, the corresponding ports, i.e. the two ports 32a and the twoports 34a, may be interconnected by piping, in the manner illustrated inFIGURE 4, to effectively provide the device with a single fluid inletand a single fluid outlet.

The modified fluid pressure device 10b of FIGURES through 7 is a fluidpump which differs from the earlier fluid pressure devices in that therotor body 38b of the pump 10b has passages 52b which communicate theinner ends of the ball vane bores 26b with the adjacent Working chambers3012, as shown, so that reciprocating motion of the ball vanes 28b intheir respective bores produces a pumping action in addition to thatproduced by expansion and contraction of the working chambers. Inaddition, the inner casing channel b in the pump 10b is circular, ratherthan elliptical as in the earlier embodiments of the invention, and iseccentrically disposed relative to the rotor axis 18b. Finally, thecasing 14b of the pump 10b has internal circumferential grooves 54bwhich provide communication between the pump ports 32!), 34b and theWorking chambers b during expansion of the chambers from and subsequentcontraction of these chambers to their minimum volume condition.

It will now be understood that the rotary fluid pump 1% of the inventionproduces, in effect, a compound pumping action involving the primarypumping action resulting from expansion and contraction of the workingchambers 30b and a secondary pumping action resulting from extension andcontraction of the ball vanes 28b in their respective containing rotorbores 2611. A major advantage of all the disclosed forms of the presentfluid pressure device, of course, resides in the fact that the ballvanes 28, 28a or 28b, as the case may be, undergo rolling movement,rather than sliding movement, along the interior surfaces of the outercasing 12. As a consequence, frictional losses and wear are reduced toan absolute minimum and the operating efficiency of the device ismaximized.

It is now evident, therefore, that the invention herein described andillustrated is fully capable of attaining the several objects andadvantages preliminarily set forth.

Although specific embodiments of the present invention have beenillustrated and described herein, it will be understood that the sameare merely exemplary of presently preferred embodiments capable ofattaining the objects and advantages hereinbefore mentioned, and thatthe invention is not limited thereto; variations Will be readilyapparent to those versed in the art, and the invention is entitled tothe broadest interpretation Within the terms of the appended claims.

What is claimed is:

1. A rotary fluid pump and motor device comprising:

an outer member having a sealed casing,

an inner member supported in said casing for relative rotation of saidmembers on an axis of rotation, one of said members having within saidcasing a circumferentially extending channel of generally semicirculartransverse cross section opening radially along one side toward theother member and bounded along its opposite side by a circularly curvedwall,

said channel having a longitudinal centerline disposed in a transverseplane of said axis and said boundary wall having a substantiallyconstant radius of curvature about said centerline along the entirelength of said channel, said other member having a number of generallyuniformly circumferentially spaced radial bores of substantially thesame diameter as said channel,

spherical ball vanes slidably fitted in said bores, respectively, andprojecting axially from said bores into said channel and into rollingfluid sealing contact with said channel boundary wall,

the circumferential extent of said channel boundary Wall about and in atransverse plane of said centerline being slightly greater than wherebysaid vanes are caged in and undergo relative rolling movement along saidchannel during relative rotation of said members,

said members and vanes defining a number of fluid chambers between theadjacent vanes, respectively, and circumferentially spaced about saidinner member, and the radial distance from said axis to said centerlinevarying progressively about said channel in such manner that duringrelative rotation of said members, each chamber undergoes alternateexpansion and contraction, and

said casing having first and second fluid ports opening to the interiorof said casing for communication with said chambers during theirexpansion and contraction modes, respectively, whereby said device isoperative as a pump by driving said members in relative rotation and asa motor by supplying high pressure working fluid to one fluid port.

2. A fluid pressure device according to claim 1 wherein:

said outer member contains said channel and said inner member containssaid bores and carries said ball vanes.

3. A rotary fluid pump and motor device comprising:

an outer member having a sealed casing,

an inner member supported in said casing for relative rotation of saidmembers on an axis of rotation,

one of said members having within said casing a circumferentiallyextending channel of generally semicircular transferse cross sectionopening radially along one side toward the other member and boundedalong its opposite side by a circularly curved wall,

said channel having a longitudinal centerline disposed in a transverseplane of said axis and said boundry wall 'having a substantiallyconstant radius of curvature about said centerline along the entirelength of said channel,

said other member having a number of generally uniformlycircumferentially spaced radial bores of substantially the same diameteras said channel,

spherical ball vanes slidably fitted in said bores, re-

spectively, and projecting axially from said bores into said channel andinto rolling fluid sealing contact with said channel boundary wall,

the angular extent of said channel boundary Wall about and in atransverse point of said centerline being slightly in excess of 180,

said other member projecting radially through the open side of saidchannel and having axially presented end faces with radial slots openingto said bores, respectively, through which said ball vanes protrude intocontact with said channel boundary wall, whereby said ball vanes arecaged by said channel for endwise movement along and against radialmovement from said channel,

said members and vanes defining a number of fluid chambers between theadjacent vanes, respectively, and circumferentially spaced about saidinner member, and the radial distance from said axis to said centerlinevarying progressively about said channel in such manner that duringrelative rotation of said members, each chamber undergoes alternateexpansion and contraction, and

said casing having first and second fluid ports opening to the interiorof said casing for communication with said chambers during theirexpansion and contraction modes, respectively, whereby said device isoperative as a pump by driving said members in relative rotation and asa motor by supplying high pressure working fluid to one fluid port.

4. A fluid pressure device according to claim 3 including:

passage means communicating the closed ends of said bores, wherebyworking fluid displaced from certain of said bores in response to inwardmovement of the ball vanes therethrough is effective to urge theremaining ball vanes outwardly and to fluid sealing relation to saidchannel boundary wall.

5. A fluid pressure device according to claim 3 including:

passage means communicating the closed ends of each bore to an adjacentfluid chamber, whereby said fluid pressure device is operative as afluid pump with a compound pumping action involving expansion andcontraction of said working chambers and extension and retraction ofsaid ball vanes in their respective bores.

6. A rotary fluid pump and motor device comprising:

an outer member having a sealed casing,

an inner member supported in said casing for relative rotation of saidmembers on an axis of rotation,

one of said members having within said casing a circumferentiallyextending channel of generally semicircular transverse cross sectionopening radially along one side toward the other member and boundedalong its opposite side by a circularly curved wall,

said channel having a longitudinal centerline disposed in a transverseplane of said axis and said boundary wall having a substantiallyconstant radius of curvature about said centerline along the entirelength of said channel,

said other member having a number of generally uniformlycircumferentially spaced radial bores of substantially the same diameteras said channel,

spherical ball vanes slidably fitted in said bores, respectively, andprojecting axially from said bores into said channel and into rollingfluid sealing contact with said channel boundary wall,

means for retaining said ball vanes in said channel,

whereby said vanes undergo relative rolling movement along said channelduring relative rotation of said members,

said members and vanes defining a number of fluid chambers between theadjacent vanes, respectively, and circumferentially spaced about saidinner member, and the radial distance from said axis to said centerlinevarying progressively about said channel in such manner that duringrelative rotation of said members, each chamber undergoes alternateexpansion and contraction,

said casing having first and second fluid ports opening to the interiorof said casing for communication with said chambers during theirexpansion and contraction modes, respectively, whereby said device isoperative as a pump by driving said members in relative rotation and asa motor by supplying high pressure working fluid to one fluid port,

said outer member comprising a stator containing said channel, and saidinner member comprising a rotor containing said bores and carrying saidball vanes,

the angular extent of said channel boundary wall about and in a planetransverse to said channel centerline being slightly in excess of andsaid rotor having axially presented end faces disposed in fluid sealingrelation to side walls of said casing and radial slots opening throughsaid faces into said bores, respectively, through which said ball vanesprotrude into contact with said channel boundary wall, whereby said ballvanes are caged by said channel for enwise movement along and againstradial inward movement from said channel, and

the periphery of said rotor projecting into said channel through openside thereof, and the outer peripheral edge of said rotor being roundedto a radius approximating the radius of curvature of said channel.

7. A fluid pressure device according to claim 6 wherein:

said casing is split into two mating halves along a parting plane normalto said axis and containing said channel centerline.

8. A fluid pressure device according to claim 7 wherein:

said rotor end faces are generally flat and disposed in planes normal tosaid axis,

said casing has inner planar sealing surfaces disposed in fluid sealingrelation to said rotor end faces, and

the diameter of said channel is slightly greater than the axial spacingbetween said sealing surfaces.

References Cited UNITED STATES PATENTS 888,838 5/1908 Muller. 1,580,1624/ 1926 Peterson. 1,965,872 7/1934 Webb et a1. 2,241,607 5/1941 Long.

JAMES W. WESTHAVER, Primary Examiner.

